Tamper evident cargo container seal bolt lock

ABSTRACT

Systems and methods for a tamper-evident cargo container seal bolt lock are disclosed herein. The device can include a receiving member, a conductive bolt member adapted to be snap-locked into the receiving member, and a plastic encapsulant which tethers the bolt member to the receiving member. The encapsulant can contain an electrically conductive medium, such as a wire, which runs from the receiving member to the second end the bolt. A sensory circuit disposed within the receiving member can be configured to sense whether the circuit has been interrupted (e.g., if the bolt has been cut). In the event of an interruption, the circuit can record the present time and/or date in memory. An RFID transponder disposed within the encapsulant or the receiving member can then transmit the recorded date/time to an RFID interrogator if a dispute subsequently arises as to when the lock had been broken.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/612,906, filed Mar. 19, 2012, the contents of which areincorporated herein by reference in its entirety as if set forth infull.

This application is related to U.S. Provisional Application No.61/609,181, filed Mar. 9, 2012, entitled: “A TAMPER EVIDENT RFID CARGOCONTAINER SEAL BOLT LOCK,” which is incorporated herein by reference inits entirety as if set forth in full. This application is also relatedto U.S. patent application Ser. No. 10/593,046 (now U.S. Pat. No.7,878,561) filed Sep. 15, 2006, entitled: “SEAL DEVICE,” which in turnclaims priority as a national stage of International Application No.PCT/DE05/02282 filed Dec. 19, 2005, and entitled “SEALING DEVICE,” whichin turn claims priority from German Application No. 10 2004 063 487.4filed Dec. 23, 2004, entitled: “SEALING DEVICE,” all of which areincorporated herein by reference in their entireties as if set forth infull.

BACKGROUND

1. Field of the Invention

Various embodiments concern the field of bolt locks for shippingcontainers. More particularly, various embodiments are directed tointelligent bolt locks which, if tampered with, can report the day andtime that they have been tampered with.

2. Related Art

Bolt locks are frequently placed on shipping containers to preventaccess to the container's contents by unauthorized parties. A bolt lockcan be locked, but it cannot be unlocked—that is to say, when thecontainer finally reaches its intended destination, the bolt has to besplit open with bolt cutters in order to access the contents of thecontainer. In this sense, a bolt lock is a one-time use device.

Typically, bolt locks include a metal bolt which is inserted through thehasps of cargo container doors. One end of the bolt includes a headwhich is substantially large enough to prevent the bolt from sliding outof the hasps in one direction. The other end of the bolt is designed tobe inserted into a receiving member. Once the bolt is inserted into thereceiving member (which is large enough to prevent the bolt from beingslid of the hasps in the other direction), the bolt is then locked intoplace.

On many occasions, a thief armed with bolt cutters will intercept theshipping container, cut the bolt, and steal the items stored within it.Sometimes, the thief will remove the broken bolt and replace it with anew bolt to make it seem as if no tampering had occurred. A discrepancybetween what items were shipped and what items actually arrived willlater be discovered in the manifest when the container arrives at itsintended destination and its contents are inspected.

In these situations, disputes frequently arise regarding which party orparties are legally responsible for covering the cost of the missingitems (e.g., the seller, shipper, purchaser, and/or various insurers).In many instances, the legally responsible party will be predicated uponwhich party had possession of the container when the theft actuallyoccurred. For example, if the theft occurred after the container waslocked, but before the container was provided to the shipper, themissing items are typically the seller's responsibility. If the theftoccurred during transit, the missing items can be the shipper'sresponsibility or its insurer (unless explicitly disclaimed in thecontract). If the theft occurred after the shipper delivered thecontainer to the purchaser's storage facility, the missing items are nolonger the seller or shipper's responsibility, but rather, it is thepurchaser's loss.

However, since the shipping container is usually opened at the end ofthe delivery chain (i.e., when it finally is in the hands of thepurchaser), the theft may have occurred at any time prior to that. Bythat time, the container has already traveled through multiple locationsand has been handled by multiple parties. Usually, visual inspection ofthe container and/or lock provides no clear evidence as to when or wherethe theft occurred. With no real way of determining when or where thetheft occurred, parties (or their insurers) often find themselves inmessy legal disputes, especially if the price of the stolen merchandiseis high.

SUMMARY

Systems and methods for a tamper-evident cargo container seal bolt lockare disclosed herein. The device can include a receiving member, aconductive bolt member adapted to be snap-locked into the receivingmember, and a plastic encapsulant which tethers the bolt member to thereceiving member. The encapsulant can contain an electrically conductivemedium, such as a wire, which runs from the receiving member to thesecond end the bolt. A sensory circuit disposed within the receivingmember can be configured to sense whether the circuit has beeninterrupted (e.g., if the bolt has been cut). In the event of aninterruption, the circuit can record the present time and/or date inmemory. An RFID transponder disposed within the encapsulant or thereceiving member can then transmit the recorded date/time to an RFIDinterrogator if a dispute subsequently arises as to when the lock hadbeen broken.

In a first exemplary aspect, a bolt lock device is disclosed. In oneembodiment, the bolt lock device comprises: a bolt member; a receivingmember adapted to receive a first end of the bolt member; an encapsulantconnected to the receiving member and to the bolt member, theencapsulant comprising a conductive medium, wherein when the first endof the bolt member has been received in the receiving member, anelectrically conductive pathway is formed from the conductive medium,through at least a portion of the bolt member and at least a portion ofthe receiving member; and a sensory circuit comprising memory, whereinthe sensory circuit is adapted to transmit electrical current throughthe electrically conductive pathway so as to detect whether the circuithas been interrupted, the sensory circuit being further adapted torecord the current date and time in the memory in the event of adetected interruption.

In a second exemplary aspect, a method for electronically detectingwhether a bolt lock has been tampered with is disclosed. In oneembodiment, the method comprises: receiving a first end of a bolt memberin a receiving member, the receiving member being connected to the boltmember via an encapsulant comprising a conductive medium, wherein whenthe first end of the bolt member has been received in the receivingmember, an electrically conductive pathway is formed from the conductivemedium, through at least a portion of the bolt member and at least aportion of the receiving member; transmitting an electrical currentthrough the electrically conductive pathway; detecting whether thesensory circuit has been interrupted; and in the event of a detectedinterruption, recording the current date and time in memory.

Other features and advantages should become apparent from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments disclosed herein are described in detail withreference to the following figures. The drawings are provided forpurposes of illustration only and merely depict typical or exemplaryembodiments. These drawings are provided to facilitate the reader'sunderstanding and shall not be considered limiting of the breadth,scope, or applicability of the embodiments. It should be noted that forclarity and ease of illustration these drawings are not necessarily madeto scale.

FIG. 1A is a perspective view of an exemplary bolt member according toone embodiment.

FIG. 1B is a cross-sectional view of the exemplary bolt member depictedin FIG. 1A.

FIG. 2 is a cross-sectional view of an exemplary receiving memberaccording to one embodiment.

FIG. 3 is a flow diagram illustrating an exemplary method ofelectronically detecting whether a bolt lock has been tampered withaccording to one embodiment.

FIG. 4 is a cross-sectional view of an exemplary bolt lock device withsensory circuit components disposed within the receiving memberaccording to one embodiment.

FIG. 5 is a cross-sectional view of an exemplary bolt lock device withsensory circuit components disposed within the encapsulant according toone embodiment.

The various embodiments mentioned above are described in further detailwith reference to the aforementioned figured and the following detaileddescription of exemplary embodiments.

DETAILED DESCRIPTION

Disclosed is a device and method for aiding with the determination ofliability for a theft by knowing when a shipping container had beenaccessed by an unauthorized party. The device is an alternative toconventional bolt seals or other types of cargo container seals andprovides a record of the time of access.

After lading a cargo container with merchandise, the doors of thecontainer are closed and locked. Upon arrival at the final destination,the lock is broken and the cargo removed and inventoried. An unbrokenlock provides evidence that the container was not opened during transit.In the event that there is a discrepancy in the manifest between whatitems were sent and what items were received, a transponder disposedwithin in the lock can be queried using a suitable reader to determinewhether a tamper event was recorded. If a tamper event was recorded, thedate and time of the event can then be transmitted to the reader. Thedate and time of the tamper event makes it substantially easier todetermine which party was in possession of the cargo container when thetamper event occurred (and consequently, which party is legallyresponsible for covering the loss).

Note that the transponder can be repeatedly queried while the containeris en route, particularly each time possession of the cargo containerchanges hands. This process can assist law enforcement since theft canbe discovered more immediately (rather than, for example, beingdiscovered upon ultimate delivery to the purchaser, which is sometimesweeks after the day that the theft occurred).

According to various embodiments, the bolt lock device includes a boltmember and a receiving member. The bolt member is intended to beinserted through one or more hasps, with one end of the bolt memberbeing inserted into the receiving member.

FIG. 1A is a perspective view of an exemplary bolt member according toone embodiment. The bolt member 102 can be made of metal or some othermaterial. As shown by this figure, bolt member 102 can have a first end104 adapted for insertion into a receiving member 202 (shown in FIG. 2),and a lock groove 116 for locking the bolt member 102 to the receivingmember 202. The second end 106 of the bolt member 102 can form a head108 which is substantially larger than the diameter of the hasps ofcargo container doors (not shown) and therefore also substantiallylarger than the diameter of the shaft 109 of the bolt. The head 108 canthus serve to prevent the bolt member 102 from sliding through the haspsof the cargo container door in a first direction.

FIG. 1B is a cross-sectional view of the exemplary bolt member depictedin FIG. 1A. As shown by this figure, the bolt member 102 can have aconductive center 110 running the axial length of the bolt. Theconductive center 110 can be made of the same material as the structuralpart of the bolt (e.g., metallic), or it can be made of a differentmaterial. In some embodiments, the conductive center 110 can consist ofconductive wiring.

According to some embodiments, the conductive center 110 can beelectrically insulated from the structural portion of the bolt. Aninsulated core within which the conductive center lies can have a smalldiameter to minimize degradation in the physical strength of thestructural part of the bolt member 102. In some embodiments, theconductive center 110 can be surrounded with a second material havingelectrically insulating material or dielectric properties.

At the first end 104 of the bolt member 102, the conductive center 110can be adapted to interface with one or electrical contacts 212 of acircuit 206 disposed within a receiving member 202 (shown in FIG. 2).For example, in some embodiments, pin connector 112 can be a femaleconnector adapted to receive one or more pins through a pin connectoropening 114 positioned at the first end 104 of the bolt member 102.

At the second end 106 of the bolt member 102, the conductive center 110can terminate at the head 108 and form a conductive pathway throughmetal in the head 108 and metal in the shaft 109 in order to completethe circuit. In other embodiments, the conductor 110 can simply wrapbackwards upon itself after it has traversed the length of the boltmember 102.

Note that while several embodiments (such as the one depicted in FIG.1B) include a conductor or conductive material 110 running through thecenter of the bolt member 102, the conductor or conductive material neednot necessarily run through the center of the bolt member 102, but canbe positioned differently in other embodiments. For example, theconductor or conductive material can be radially offset by some distancefrom the center of the shaft 108, including, for example, beingpositioned at a radial edge of shaft 109. Also, according to someembodiments, the conductor or conductive material can run throughmultiple locations of the bolt member 102.

FIG. 2 is a cross sectional view of an exemplary receiving memberaccording to one embodiment. The receiving member 202 can be configuredto receive the bolt member 102 inserted therein and prevent itswithdrawal, thereby locking it into place. In some embodiments, lockring 204 disposed within the receiving member 202 is adapted tointerface with lock groove 116 (shown in FIG. 1A) in order to facilitatethe locking.

Receiving member 202 can include a circuit 206 adapted to interface withconductive center 110 (shown in FIG. 1B) via a set of electricalcontacts 212. In some embodiments, for example, electrical contacts 212can include a set of connectors, such as one or more mating pins adaptedto be inserted with pin connector 112 of the bolt member 102. Instead ofmating pins, note that other types of electrical contacts 212 can beused in the alternative.

Thus, the first end 104 of the bolt member 102 can be shapedspecifically to facilitate its insertion into the receiving member 202,and to electrically interface with one or more electrical contacts 212formed in the receiving member 202. In some embodiments, when the firstend 104 of the bolt member 102 is inserted into the receiving member202, a continuous circuit is formed from one electrical contact 212through the conductive center 110, across length of the bolt member 102,up to its head 108, returning through the metal material of which thebolt is made, and then back to a second electrical contact 212.

In some embodiments, the circuit 206 can be a sensory circuit configuredto sense whether the circuit is continuous or has been interrupted(i.e., whether it is a “short” or “open” circuit). Thus, if theconductive center 110 running the axial length of the bolt member 102has been severed (for example, if bolt member 102 has been cut with boltcutters) the circuit 206 can therefore detect this condition. Personsskilled in the art will appreciate that circuit 206 can be designed in anumber of different manners and/or circuit arrangements in order toaccomplish this purpose.

In order to provide power to the circuit 206, a battery 208 can bemolded or otherwise included in the receiving member 202. This battery208 can be used in order to enable operations of timekeeping, event anddata logging, and other functions. Batteries 208 of any type can be usedfor this purpose, such as button or coin cells, or thin-film batteries.In some embodiments, the receiving member 202 can be configured toconnect the battery 208 to the circuit 206 only when the bolt isinserted, i.e. when the container is sealed, in order to maintainbattery charge while on the shelf.

The circuit 206 can also include a processor, memory, and a timingcircuit or clock (not shown), the latter component for keeping track ofthe current date and/or time. Thus, according to some embodiments, whenthe circuit 206 is detected to be open or short, the present date and/ortime can be written to memory. This serves as evidence as to when thetamper event occurred. In some embodiments, the memory can also store atransaction record of intermediate events that occurred during thecourse of travel or shipment, such as times and places of transfers.This information can further assist in pinpointing the exact location ofthe shipping container when the tamper event occurred.

In some embodiments, the state of the condition of the circuit 206(i.e., whether the circuit has been shorted or opened) can be polled atperiodic intervals in order to extend the operational life of battery208. For example, in some embodiments, a polling event can take placeevery five minutes. The regularity of polling can be adjusted tocorrespond with the operational life of the battery 208 and/or the totalexpected time of delivery of the shipment.

In some embodiments, the circuit 206 can also include a transponder 210and an antenna 214. The transponder 210 can comprise a single chip, or acombination of chips and components forming a wireless communicationmeans. In one embodiment, for example, the chip is an RFID chipoperating in the UHF frequency band and complying with the ISO 18000-6Cor EPC C1G2 standard. Other chips can also be applied, including thoseoperating in the HF frequency band and compliant with ISO 14443A/B orISO 15693, Bluetooth, Zigbee, or proprietary technologies. In someembodiments, electrical contacts 212 can connect with contact pins whichare part of the transponder 210.

The transponder 210 can be connected to antenna 214, which serves toreceive and transmit signals to a reader or interrogator. The one ormore batteries 208 can be used to power the transponder, eithercontinuously or intermittently.

In some embodiments, the transponder 210 can contain a unique identifierand other information related to the nature of the shipment and itscontents. This data can be stored in a memory module local to thetransponder 210 or in another memory source associated with circuit 206.

In other embodiments, a serial or parallel bus connection, rather than awireless transponder, can be used to read/write data to memory of thecircuit 206. For example, a USB, FireWire, or RS-232 port can beincluded within receiving member 202. If an arrival time and location isto be written to the memory of the circuit 206 (for example, when theshipping container is being transferred from ship to train), a handhelddevice with a connecting serial bus cable can transmit the data to bewritten through the serial bus cable to the memory. Conversely, if thecontents of the memory are queried in order to determine if a tamperevent occurred, the requested data can be transmitted from memory of thecircuit 206 over the serial cable to the querying device.

FIG. 3 is a flow diagram illustrating an exemplary method ofelectronically detecting whether a bolt lock has been tampered withaccording to one embodiment.

At block 302, a first end of a bolt member is received in a receivingmember. The first end of the bolt member can be specifically shaped forinsertion into the receiving member, such that the bolt member can belocked in the receiving member upon or after insertion. A sensorycircuit disposed within the receiving member can be adapted toelectrically interface with a conductive medium running the axial lengthof the bolt member. For example, one or more mating pins canelectrically interface with a female pin connector through a pinconnector opening at a first end of the bolt member.

When the circuit is connected to a power source, such as a battery,electrical current can then run from a first mating pin through theaxial length of the bolt and back to a second mating pin in order toform a continuous circuit. If the circuit is severed (for example, thebolt is cut), the circuit can then detect an interruption (e.g., an openor short circuit). This condition can be checked continually orperiodically according to various embodiments. Blocks 304 and 306 depictthis process.

In the event of a detected interruption, then at block 308, the presentdate and time can be written to a local memory module. This data servesas evidence as to when the tamper event occurred. Optionally, the datastored within this memory can subsequently be transmitted to an externaldevice in response to a query transmitted from a wireless transceiver(e.g., an RFID interrogator) or over a serial bus cable.

In some embodiments, the memory of the bolt lock device can be writtento as well. These write operations can be used, for example, in trackinga container as it is shipped through multiple locations and/or as thecontainer is transferred between multiple parties. By periodicallywriting to the memory of the bolt lock device as the device changeslocations and/or handling parties, a location log and date-stamp can begenerated to facilitate more immediate discoveries of tamper events. Inthis manner, tamper events can be discovered well before the shippingcontainer arrives at its intended destination.

In order to facilitate a simpler assembly of the bolt lock device and toimprove the strength and/or structural integrity of the bolt member,various alternative embodiments of the bolt lock device are describedbelow. Note that these embodiments can also have the advantage ofcosting less to manufacture, thereby decreasing the sales price of thefinished product.

FIG. 4 is a cross-sectional view of an exemplary bolt lock device withsensory circuit components disposed within the receiving memberaccording to one embodiment. As shown by this figure, exemplary boltlock device 400 can include a bolt member 102, a receiving member 202,and an encapsulant 402 connected to both the bolt member 102 and thereceiving member 202. In effect, the receiving member 202 and the boltmember 102 are tethered to each other by the encapsulant 402. This hasthe further advantage that the bolt lock device 400 is a single unitrather than two parts which may become separated, lost, or accidentallyswitched with a similar component from a different bolt lock device 400.

In the embodiment depicted by FIG. 4, many of the components of thesensory circuit 206 are contained within the receiving member 202. Thismay include, for example, a transponder 210, an antenna 214, and one ormore batteries 208. Note that a serial bus interface (e.g., USB,Firewire, RS-232, etc.) can be used in addition to or in lieu oftransponder 210 and antenna 214 according to some embodiments.

In the embodiment depicted by FIG. 4, a portion of the electrical loopwhich detects tampering can be partly external to the bolt member 102and the receiving member 202, formed within an encapsulating material.This encapsulant 402 can be made of flexible and durable material, suchas certain plastics. A circuit wire 404 or other conductive medium canbe routed from a part of the circuit 206 disposed within the receivingmember 202 through the encapsulant 402 and connect electrically and/ormechanically with the second end 106 of the bolt member 102 (forexample, it can connect with the head 108 of the bolt member 102, seeFIG. 1A).

Rather than running an electrical wire or separate conductive mediumthrough an electrically insulated region in the bolt member 102 (forexample, through an insulated core extending axially across the lengthof the bolt), the bolt member 102 can have a solid interior according tosome embodiments. This simplifies manufacture as the bolt member 102does not require special processing in order to ensure that there is anadequate opening for a separate conductive medium. Instead, thestructural portion of the bolt member 102 can itself serve to conductelectrical current in a single direction.

Thus, when the bolt member 102 has been received in the receiving member202, an electrically conductive pathway can be formed from a firstconnecting pad (or pin) of the transponder 210, through an external wire404 in the encapsulant 402, to the second end 106 of the bolt member102, and return to a second connecting pad (or pin) of the transponder210. Electrical continuity between the bolt member 102 and the secondconnecting pad (or pin) of the transponder 210 can be formed by aconnection to a spring contact, or alternatively, to the lock retainingring 204 (see FIG. 2) that is part of the receiving member 202. Thus,when the bolt member 102 has been received in the receiving member 202,a continuous electrical circuit is formed.

As in the previous examples, the transponder 210 can comprise a singlechip, or a combination of chips and components forming a wirelesscommunication means. In one embodiment, for example, the chip is an RFIDchip operating in the UHF frequency band and complying with the ISO18000-6C or EPC C1G2 standard. Other chips can also be applied,including those operating in the HF frequency band and compliant withISO 14443A/B or ISO 15693, Bluetooth, Zigbee, or proprietarytechnologies.

FIG. 5 is a cross-sectional view of an exemplary bolt lock device withsensory circuit components disposed within the encapsulant according toone embodiment. As shown by FIG. 5, exemplary bolt lock device 500 canbe structured and arranged similarly to exemplary bolt lock device 400of FIG. 4, except that the components of the circuit 206 (e.g., thetransponder 210, the battery 208, and the antenna 214) can be disposedwithin the flexible “tether” encapsulant 402 which connects thereceiving member 202 to the bolt member 102. This configuration cansimplify the construction and assembly of the receiving member 202, asit is significantly easier to place the transponder 210, antenna 214,battery 208, and connections to the loop wire 404 in the encapsulant 402than to assemble the components in the body of the receiving member 202.These circuit components can be made flexible or rigid as required,preassembled onto a substrate, and encapsulated as a unit according tosome embodiments. A number of methods for encapsulation may be used forthis purpose (for example, over-molding).

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notof limitation. The breadth and scope should not be limited by any of theabove-described exemplary embodiments. Where this document refers totechnologies that would be apparent or known to one of ordinary skill inthe art, such technologies encompass those apparent or known to theskilled artisan now or at any time in the future. In addition, thedescribed embodiments are not restricted to the illustrated examplearchitectures or configurations, but the desired features can beimplemented using a variety of alternative architectures andconfigurations. As will become apparent to one of ordinary skill in theart after reading this document, the illustrated embodiments and theirvarious alternatives can be implemented without confinement to theillustrated example. One of ordinary skill in the art would alsounderstand how alternative functional, logical or physical partitioningand configurations could be utilized to implement the desired featuresof the described embodiments.

Furthermore, although items, elements or components may be described orclaimed in the singular, the plural is contemplated to be within thescope thereof unless limitation to the singular is explicitly stated.The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent.

What is claimed is:
 1. A bolt lock device comprising: a bolt member; areceiving member adapted to receive a first end of the bolt member; anencapsulant connected to the receiving member and to the bolt member,the encapsulant comprising a conductive medium, wherein when the firstend of the bolt member has been received in the receiving member, anelectrically conductive pathway is formed from the conductive medium,through at least a portion of the bolt member and at least a portion ofthe receiving member; and a sensory circuit comprising memory, whereinthe sensory circuit is adapted to transmit electrical current throughthe electrically conductive pathway so as to detect whether the circuithas been interrupted, the sensory circuit being further adapted torecord the current date and time in the memory in the event of adetected interruption.
 2. The bolt lock device of claim 1, wherein thebolt member comprises metal.
 3. The bolt lock device of claim 1, whereinthe conductive medium comprises electrical wiring.
 4. The bolt lockdevice of claim 1, wherein the encapsulant comprises plastic.
 5. Thebolt lock device of claim 1, wherein a second end of the bolt membercomprises an electrically conductive head having a diameter that islarger than the diameter of the rest of the bolt member.
 6. The boltlock device of claim 5, wherein the conductive medium is adapted toelectrically interface with the conductive head.
 7. The bolt lock deviceof claim 7, wherein the sensory circuit further comprises a serial busconnection.
 8. The bolt lock device of claim 1, wherein the sensorycircuit further comprises a transponder, an antenna, and a battery. 9.The bolt lock device of claim 8, wherein the transponder, the antenna,and the battery are disposed within the receiving member.
 10. The boltlock device of claim 8, wherein the transponder, the antenna, and thebattery are disposed within the encapsulant.
 11. The bolt lock device ofclaim 8, wherein the transponder comprises an RFID chip.
 12. The boltlock device of claim 8, wherein the battery comprises a cell battery.13. The bolt lock device of claim 8, wherein the battery comprises athin-film battery.
 14. The bolt lock device of claim 8, wherein thebattery is adapted to electrically connect with the sensory circuit onlyif the first end of the bolt member has been received in the receivingmember.
 15. A method for electronically detecting whether a bolt lockhas been tampered with, the method comprising: receiving a first end ofa bolt member in a receiving member, the receiving member beingconnected to the bolt member via an encapsulant comprising a conductivemedium, wherein when the first end of the bolt member has been receivedin the receiving member, an electrically conductive pathway is formedfrom the conductive medium, through at least a portion of the boltmember and at least a portion of the receiving member; transmitting anelectrical current through the electrically conductive pathway;detecting whether the sensory circuit has been interrupted; and in theevent of a detected interruption, recording the current date and time inmemory.
 16. The method of claim 15, further comprising: receiving arequest from an external device to read memory content; and in responseto the request, transmitting data indicating the recorded date and timeto the external device.
 17. The method of claim 16, wherein transmittingdata indicating the recorded date and time to the external devicefurther comprises wirelessly transmitting data indicating the recordeddate and time to the external device.
 18. The method of claim 16,wherein transmitting data indicating the recorded date and time to theexternal device further comprises transmitting data indicating therecorded date and time to the external device over a serial bus cable.19. The method of claim 15, further comprising: receiving a request froman external device to write data to memory; in response to the request,writing the data to the memory.
 20. The method of claim 19, wherein thedata comprises a location and a date.